The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2013
Filed:
Aug. 22, 2011
Yuchen Zhou, Milpitas, CA (US);
Kenichi Takano, Cupertino, CA (US);
Kowang Liu, Fremont, CA (US);
Kunliang Zhang, Milpitas, CA (US);
Liejie Guan, San Jose, CA (US);
Moris Dovek, San Jose, CA (US);
Joe Smyth, Aptos, CA (US);
Yuchen Zhou, Milpitas, CA (US);
Kenichi Takano, Cupertino, CA (US);
Kowang Liu, Fremont, CA (US);
Kunliang Zhang, Milpitas, CA (US);
Liejie Guan, San Jose, CA (US);
Moris Dovek, San Jose, CA (US);
Joe Smyth, Aptos, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
A PMR writer is disclosed that minimizes pole erasure during non-writing and maximize write field during writing through an AFM-FM phase change material that is in an anti-ferromagnetic (AFM) state during non-writing and switches to a ferromagnetic (FM) state by heating during writing. The main pole layer including the write pole may be comprised of a laminated structure having a plurality of 'n' ferromagnetic layers and 'n−1' AFM-FM phase change material layers arranged in an alternating manner. The AFM-FM phase change material is preferably a FeRh, FeRhPt, FeRhPd, or FeRhIr and may also be used as a flux gate to prevent yoke flux from leaking into the write pole tip. Heating for the AFM to FM transition is provided by write coils and/or a coil located near the AFM-FM phase change material to enable faster transition times.